Automatic carriage return mechanism for typewriters



July 9, 1935- F. w. LE PoRlN 2,007,653

AUTOMATIC CARRIAGE RETURN MECHANISM FOR TYPEWRITERS Fileql Nov. 30, 1954 5 Sheets-Sheet 1 lllllllllllllm Z ATTORNEY' I July 9, 1935. F, w. LE PoRlN 2,007,653

AUTOMATIC CARRIAGE RETURN MECHANISM FOR TYPEWRITERS Filed Nov. 30, 1934. 3 Sheets-Sheet 2 INVENTOR.

July 9, 1935. F. w. LE PoRlN 2,007,653

AUTOMATIC CARRIAGE RETURN MECHANISM FOR TYPEWRITERS I Filed NOV-i 30. 1934 3 Sheets-Sheet 3 lll .Patented July 9, 1935 2,007,653 .amor/mmc casamos RETURN mona' NHSB/l FOR 'E YPEWRITERS Frederic W. Le Parini, Brooklyn, N. Y. applicaties Nsvember at, 193i, serial No. 755,316

y'1l Claims.

This invention relates to automatic-return mechanism for carriages of typewriting machines, and provides improvements therein.

The invention provides an automatic carriagereturn mechanism which can be applied to typewriters of the kinds in general use (in which the carriages are manually returned) with virtually no alteration of the mechanism` of the typewriter, with a minimum of additive parts, and

with no alteration of the normal functioning of the typewriter, the automatic-return mechanism functioning collaterally or alternatively with the manual return operation. 'v

The invention further provides automatic carriage-return mechanism which will stall easily when a hand or a finger of the operator, or other object, is in the path oi' the carriage during its automatic return, to thereby avoid accidental injury to the operator, or to the machine.

The invention further provides a mechanism which may be economically built, comprising in large part metal parts which may be formed by stamping operations, and the parts of which may be assembled with a minimum of special tting.

The invention further provides a mechanism which will operate satisfactorily notwithstanding moderate deformations of the parts due to rough treatment of the typewriter, inaccuracies of alinement, etc., in assembling' the parts, and in attaching the mechanism to a typewriter.

The invention also provides a mechanism which operates easily, without violent shocks, and in which the operation of the elements, following the operation of a key to start the carriage-return and the operation of mechanism for stopping the carriage return, is automatic, instantaneous and timed so as to obtain the best coaction. The improved mechanism provides for the easy disengagement of a clutch under the conditions of its use in such a mechanism.

An embodiment of the invention is illustrated in the accompanying4 drawings, wherein:

Fig, 1 is a top-plan view of the carriage-return mechanism, with parts of the typewriter r structure also shown.

tiox. of the carriage-return mechanism, the parts being shown in the position in which the motor is cut oi and also in the position in which they are when the typing mechanism is being used.

Fig. 4 is a view similar to Fig. 3, and showing the key for starting the operation of the carriage-return mechanism depressed to the position Where the carriage-return mechanism is put into operation.

Fig. 5 is a top-plan view of parts illustrated 5 in Fig. 3.

Fig. 6 isa detail view shown in' Fig. 3.

Fig. 7 is a detail view of the upper horizontal lever shown in Fig. 5.

Fig. 8 is a detail view of a bracket which is attached to the typewriter, and which is provided with pivotal supports for the levers shown in Figs. 6 and 7.

Figs. 9 and 10 are respectively a cross-section 15 and a top-plan view of parts mounted on the movable carriage and on the stationary frame of the typewriter, respectively, which co-act to initiate the stopping of the carriage-return motor, when the carriage has completed its return move- 20 ment, as determined by the marginal stops of the typewriter, which marginal stops appear in the gures.

Fig. 11 is a top-plan View of the parts of the carriage-return mechanism (including the motor, 25 speed-reduction gearing and clutch) shown at the right in Fig. 1.

Fig. 12 is a vertical sectional view on line XII- XII of the parts shown in Fig. `11.

Fig. 13 is a transverse sectional view on line 30 XIII-XIII, Fig. 12.

Fig. 14` is an end view in Fig. 12.

Fig. 15 is a vertical sectional view of the drum and associated parts shown at the left of Fig. 1. 35

Referring to said drawings, the stationary parts of the typewriter to which the carriage return mechanism is attached, or is to be attached, are indicated by the reference letter S; and the Inov' able spring-tensioned carriage by the letter C.

The carriage-return mechanism comprises a frame l0, which is conveniently formed by stamping from a sheet of metal of moderate thickness, and on which most of the parts of the carriage# return mechanism are mounted. As here shown, frame I0 is conveniently of an L shape and provided with punched portions I2, i3 'and Hi which are designed to t beneath the feet l5 of the typewriter, and frame lll may be attached to the typewriter by removing the feet l5, passing the screws I6 of the feet through the holes in the portions l2, I3 and M of the frame, and then fastening the screws i6 in the threaded sockets therefor in the frame of the typewriter. 'Ihere are only two other parts which are required for of the long vertical lever of certain parts shown attachment to the typewriter. One is the bracket I8 shown in Fig. 8, which is attached to the typewriter by removing the screw I9 (Figs. 1 and 5) which fastens the top-plate of the typewriter to one of the vertical posts of the typewriter frame, passing the screw I9 through the hole 20 provided therefor in the bracket I8, and then replacing the screw I9 to fasten the bracket I8 to the top-plate of the typewriter and the topplate to the vertical post. The other part is a. small plate 22 (Fig. 10) provided with a beveled face or cam 23, which plate 22 is formed on or fastened to the adjustable abutment 24 which latter is carried by the carriage C and co-acts with the marginal stop 26 pivotally mounted on the typewriter frame S, as indicated at 21; The bracket I8 is a simple part which may be formed by punching and bending a piece of sheet-metal.

Mounted on the frame I0 is an electric motor 30, and adjacent the motor is the housing 32 of a speed-reduction gearing 33, also mounted on the said frame I0. Numeral 34 designates a drum which is connected with the speed-reduction gearing 33 by shaft 36, and which drum 34 has attached thereto a flexible cord or tape 38 which is attached to the movable carriage the side of C, and preferably to the lever L of the linespacing mechanism on the caniage, the tape at the typewriter passing over a roller 40 which is mounted on the bracket |8 which is attached to the typewriter frame.

The motor preferably drives the drum 34' through a clutch 44.

'I'he speed-reduction mechanism 33 preferably comprises shafts 59 and 5| having meshing helical gears 53, 54 thereon. The helical gears are of a type through which motion may be transmitted with equal facility in either direction, and are to be distinguished from worm gears which resist backward turning. Ball thrust-bearings 55, 56 are provided for shaft 53, so that it may turn easily. A ball thrust-bearing 58 is also provided for the gear 54, so that the thrust thereon from the gear 53 will be sustained in a manner which admits of easy turning. The gear 54, in the embodiment here illustrated, being loose on the shaft 5|, is maintained against axial movement, and, as all of the thrust is against the bearing 58, a simple device, as a pin 59, may be provided for this purpose.` The pin 59 may be fastenedon the housing 32, and be arranged so that its inner end projects within a small distance of the side of the gear 54.

The clutch 44, as shown in the embodiment here illustrated, may be combined with the speedreduction gearing 33. The gear 54 may have fixed thereon a jaw-plate 6 I, and opposite thereto, and fixed on shaft 5|, is a companion jawplate 62. The shaft 5| is axially movable in its bearings, and such axial movement, to bring the jaws 6| and 62 into and out of clutching engagement, is effected through suitable means, as a g'rooved collar 65 fixed on shaft 5|, and a two-armed shift lever 66, 61, which may be pivoted in a bracket 68, fastened on the housing 32, as indicated at 69, Figs. 11 and 14. The shiftlever 66, 61 is acted upon by a spring 1| in a direction to move the shaft 5| axially to bring the jaws 6|, 62 of the clutch into engagement.

The shaft 36 is conveniently supported at its end adjacent the reduction gearing in a forked bearing 15 engaging a groove in a collar 16 fastened on the said shaft 36, and thereby prevents axial movement of said shaft 36. At its opposite end the shaft 36 is supported on a stud 18, formvThe spring I I I ing part of the drum-support, and hereinafter more fully described, The shaft 36 turns without being subjected to thrust at either end.

The drive-shaft 8| of the motor 30 is preferably connected to the shaft 53 of the speed-reducing gearing 33 through a universal connection 84. The universal connection 84 may have the simple form of two proximate disks 86, 81 fastened on the respective shafts 8|, 53, connected by an eccentric pin 88 projecting from the face of one disk and into a notch 89 in the other disk. The drum-shaft 36 is also preferably connected to the shaft 5| of the speed-reducing gearing 33 through a universal connection 92. The universal connection 92 may have the simple form of a disk 93 fixed on the shaft 36 and projecting within a cupped disk 95 fixed on the shaft 5|, the two disks being coupled through a pin 96 projecting from the periphery of disk 93 into an elongated slot 91 in the peripheral portion of the cupped disk 95. By providing the universal joints 84 and 92 between the motor 30 and the speed-reducing gearing 33, and between the speed-reducing gearing and the drum-shaft 36, (and also the universal connection |40 hereinafter described) niceties of assembling the parts to obtain easy running are avoided, and the frame I0 on which the parts are mounted can have a moderate distortion due torough handling, or may have initial irregularities of form, without interfering with or preventing the easy running of the parts of the carriage-return mechanism.

Numeral |00 designates a switch for controlling the flow of current to the motor 30. This switch I00 is conveniently located within the housing 32, as shown in Figs. 12 and 13. The switch comprises a fixed contact |0| and' a movable contact |02. spring-arm |03. Opposite the spring-arm |03 is arranged a pin or projection |04 which flexes the arm |03 when the arm |03 is moved against said pin. The position of the pin |04 with respect to thc spring-arm may be made adjustable as by means of a screw-thread connection |01 between it and the housing 32. The switch |00 may be mounted on a plate |05, which is pivotally mounted as indicated at |06, and which plate has an arm |08 having a projection |09 for a purpose hereinafter explained. The plate |05 carrying the switch |00 is acted on by a spring in a direction to bring the arm |03 on which the contact |02 is mounted into contact with the pin |04, and to thereby move the contacts |0|, |02, together to complete the circuit to the motor 30. is conveniently attached at one end tothe arm |08 of the plate |05, and at its other end to a part fixed on the frame l0.

The position of the projection |04 may be adjusted so that the making and breaking of the circuit to the motor 30 may be timed with relation to the engagement of the jaws of clutch 44. The preferred timing is such that the clutch 44 is partially engaged before turn shaft 50, and the circuit to the motor 30 broken before or during the disengagement of the clutch 44.

The drum 34 is conveniently mounted on a hollow stud ||6 (Fig. 15) fastened upon a bracket |6,. fastened to the frame I0, and which bracket I8 may be conveniently formed of stamped sheetmetal. Ball bearings |20, |2| are preferably provided between the drum 34 and its support, so that the said drum may turn easily under the pull of the tape 38 during the return of the carriage C. The outer race of the ball bearing |2| the motor begins to' The ymovable contact |02 is carried on a drum-shaft 36.

` normally holding the clutch parts 6| part |24 also carries the stud 18, hereinbefore,v

referred to, which supports the adjacent end of 'Ihe drum 34 is alsopreferably acted-upon by a coiled spring |30 (Fig. 15), one end of which is connected to a flange on the drum, as indicated at |32, and the other end of which, as indicated at |33, is connected to a sleeve |34 fastened to the bracket H8. The spring |30 acts in a direction to turn the drum 34 in a direction to maintain a slight tension or pull on the tape 38, so

that thepul'l of the spring |30 on the drum will maintain tautness of the tape 34 'throughout all movements of the carriage which occur when the motor 30 is not' acting through the drum to effect the return ofthe carriage.

The drum-shaft 36 is preferably connected to the drum 34 through a universal joint |40, which joint may have the simple form ofa disk |42 xed to shaft 36 and having an eccentric pin |43 thereon fitting into a socket |45 on the adjacent side of the drum. The universal joint |40 allows the drum 34 to be turned easily by the shaft 36, notwithstanding slight inaccuracies in alinement, due to irregularities in frame l0 yand other causes hereinbefore referred to.

As a part of the means for controlling the operation of the motor 30, a reciprocatory part or bar |50 is provided. This bar is conveniently in' the form of a flat strip extending alongside of the frame of the typewriter, and having limited longitudinal movement. The bar |50 mayv be supported in simple brackets |52, |53 formed of sheet-metal and attached to the frame |0 of the attachment, the brackets |52, |53 being provided with headed pins |55.which pass throughl Ielongated slo'ts |51 in the said bar |50. The bar |50 has therein an elongated notch |60, within which the projection |09 on the arm |08 of the switch 00, extends. The bar |50 also has thereon a pin |62 which extends across the arm 61, as shown in Figs. 12, 13 and 14. The bar 50 also has thereon a pin |64 (Figs. 1 to 5) which is adapted to be engaged by a detent |66 which may be pivotally mounted on'the bracket ||8, as indicated at |61. The bar |50 also has thereon a pin |10 which is adapted to be engaged by a pawl |12 on a key-lever |15 which is adapted to be struck for eiecting the return of the carriage C through the automatic return mechanism here-- inbefore described.

The bar |50 is acted on by a predominant spring |80, and the action of the spring is tonormally hold the bar in the position shown in Fig. 3

Where an abutment |8| thereon rests against a.

stop |82 fastened on the frame l0 of the attachment. `The pin |62 on the bar (Figs. 12, 13 and 14) bears on the arm 61 of the clutchshift-lever, and 62 in their disengaged position. The notch |60 in the bar |50 also normally engages the projection' |09, and holds the switch |00 out of position to complete the'circuit to thelmotor through the action of projection |04 on contacts |0| and |02. The

pin |64 on the bar normallyl lies above the detent |66, and holds it depressed. When the pin l| 64 on the bar |50 has been engaged by the detent |66, and the detent |66 is thereafter moved to disengage the pin 64 the force of the predominant spring |80 is such as -to overcome the force of the spring actingV on the arm |08 of the switch and 5. The detent |00, and also to overcome the force of the spring 1| acting on the shift-levers 66, 61 of the clutch, and shoot the bar' |50 to the position shown in Fig. 3, as hereinafter described.

The key-lever |15 is pivoted as indicated at |83 (Figs. 3,' 4 and 5) to a Abracket |84 (which is 4preferably a stamped metal part) fastened to the frame I0 of the attachment. A spring |86 attached at one end to the key-lever 1.5 and atits other end-to an arm |81 on said bracket |84 normally acts'to hold said key-lever up, as indicated in Fig. 3. The movement of the key-lever |15 around its pivot is limited by a pin |9| projecting from the bracket |84 into a slot |93in the said key-lever |15. The pawl |12 is pivotally attached to the key-lever |15, as indicated at |95. The movement of the pawl |12 around its pivot |95, is, however, limited by a pin |91 thereon extending into a slot |98 in the key-lever. The pivotal mounting of the pawl |12 and the shape of the tooth of the pawl enable the pawl to slip quickly out of engagement with the pin |10 after the bolt |59 has been advanced to a position where the detent |66 is able to rise and engage the pin |64. A spring |99 acts on said detent in a direction to turn it toa position to engage the pin |64. The pin |64 may-be mountedgon a plate 202 which is adjustable with respectv to the bar |50, so that the proper timing of the engagementof the pin |64 by the detent |66 following the release of the :pin |10 on the bar |50 by the pawl |12 on the keyframe, may be as follows: Pivoted on the bracket |8, as indicated at 20,4, Fig. 3, is a lever 205, and co-acting with said lever 205 is a lever 201 pivoted to said bracketl I8, as indicated at 209, Figs. 1 |66 hasthereon a pin 2|| which is adapted to be engaged by the end of said lever 205. A spring 2|3 connected to said lever 205 and to an arm 2 5 on said bracket I8 normally tends `to hold the lever 205 out of the range of movement of said pin 2| on detent |66. The lower end of said lever 205 is, however, made adjustable, so that the action of said lever 205 on the detent |66 may be properly timed. The adjustment may be eiectedby providing the lever 205 with an extension 220 (Fig. (i) which is pivoted to the lever 205, as indicated at 222, and which is made fast in its adjusted positions by means of a binding-screw 223. Numeral 225 designates a cam-screw by means of which fine adjustments of vsaid extension 220 may be made when the binding-screw 223 is loosened. K

In the form of typewriter here illustrated, the lever 201 is held with its end 230 in contact with the pivoted marginal stop 26 on the frame of the typwriter When the abutment 24 carried by the carriage C is provided with a cam 23, as hereinbefore described, and when contact withv the marginal stop 26, the said marginal stop 26 is caused to turn rapidly on its pivot. The marginal stopbeing in contact with the lever 201 at its end 230, imparts movement to the lever 201 around its pivot 209,' and the lever 209 acting upon the lever 205, turns this latter lever 205 around its pivot 204, and brings its end against the pin 2|| on the detent detent 'out of the path vofthe-pin |64 onb'ar 150,

and thus allowingthe -predominantkspring .|80 y i Y' 1 .l 1 i I f/ as the carriage `reaches thel this 'cam 23 makes |66, thus moving the l |12 slips off of the pin to bring the abutment |8| on the bar |50 against the stop |82, in which position, as hereinbefore described, the motor 30 is deenergized and disconnected.

Because of the light and easy running of the mechanism provided by the ball-bearings 55, 56, 58, |20, |2|, and the non-binding driving connections through the universal joints 84, 92 and |40, the motor 30 maybe one of minimum power for doing the work of returning the carriage, and in practice I make use of a motor having about 1/64 horsepower, or slightly in excess of that required to move the carriage against the opposing force of the carriage spring. This construction and arrangement, especially when combined with the gears (such as the helical gears 53, 54) which transmit motion with equal facility in either direction, has multiple advantages. The shock when the abutment 24 on the carriage and the marginal stop 26 come together is mild. The clutch parts may move instantly out of disengagement under the influence of a comparatively light spring. The motor stalls easily when an obstruction is met by the carriage, damage to the typewriter and injury to persons are avoided, and by reason of the easy reverse turning of the special type of gears which are' provided, an object which is `caught between the carriage and a fixed part of the typewriter is not held but is easily released. Moreover the force of the blow is small because of the mechanical disadvantage at which the motor works through the speed-reduction gears, and is resilient because of the capabilityv of. easy reverse movement of the parts.

Operation To return the typewriter carriage from any position to which it may be advanced by the operation of the type-bar key-levers, the carriagereturn key |15 is struck. The position of the parts prior to the striking of the key-lever |15 is illustrated in Fig. 3, and the position of the parts after the striking of the key-lever |15 is illustrated in Fig. 4. When the lever |15 is struck, it moves around its pivot |83, bringing the pawl |12 thereon into contact with the pin |10 on the bar |50. The pawl |12 moves the bar |50 to the right in the drawings, and as the key-lever |15 approaches the limit of its turning movement, the detent |66 rises under the force of its spring |99 to a position behind the pin |64 on the bar |50. At about the same time the pawl |10 and releases the-bar |50, after which the bar is retained by the detent `|66. Upon the release of the key-lever |15, its

spring |66 restores it to its normal position (shown in Fig. 3), the pawl |12 turning on its pivot |95 on the return movement of the keylever so as to pass over the pin |10.

As the bar |50 is projected to the right under the action of the key-lever |15, the edge of slot |60 moves away from the projection |09 on the switch-lever |08 (Fig. `13) and the pin |62 moves away from the arm 61 of'the clutch-lever, which allows the shaft 5| to move quickly to the left under the influence of the spring 1 I, and thereby bring the clutch part 62 into engagement with the clutch part 6|. Practically simultaneously with the movement of the shaft 5|, but with enough time difference to allow the clutch parts to partially engage before the motor 30 starts, the switch is rapidly turned under the influence of its spring to establish the motor circuit through the contacts |0 I, |02. The motor thereupon starts, driving the shaft 50 of the speed re- 'force the motor 30.

ducing means 33 through the universal connection 84. The helical gear 53 drives the helical gear 54, and the gear 54 being connected to the shaft through the clutch parts 6|, 62 rotates the said shaft 5|, and the said shaft 5| through the universal connection 92 drives the drumshaft 36. The drum-shaft 36 being connected to the drum 34 through the universal connection |40 (Fig. l5) rotates the said drum, winding the tape 38 thereon, and the winding tape pulls the carriage C until the abutment 24 on the carriage is brought to a stop against the marginal stop 26 (Figs. 9 and l0). The tape 38 being connected. to the line-spacing lever L on the carriage, however, first moves the lever L to rotate the platen of the carriage C a distance corresponding to the spacing to be made between lines, and thereafter the pull of the tape 38 on the lever L moves the carriage on its return movement, as just described.

The action of the carriage-return mechanism is automatically stopped as follows: As the carriage returns to within about one space of its limit of movement permitted by the abutment 24 and marginal stop 26, the cam 23 (Figs. 3, 9 and 10) strikes the edge of marginal stop 26, causing it to turn with great rapidity. The'turning movement of the marginal stop 26 produces a turning movement of the lever 201, and this turning movement of the lever 201 causes a turning movement of the lever 205. The movement of the lower end of lever 205 against the detent 2|| on detent |66 moves the detent out of engagement with the pin |64 on the bar |50, and the bar being thereby released shoots quickly tp the left under the influence of the predominant spring |80; and the contact of the edge of notch |60 (Fig. 13) with the projection |09 on the arm |06 turns the switch |00, to move the arm |03 carrying the movable contact |02 away fromprojection |04, to quickly break the circuit at the contacts |0|, |02, and, at about the same instant the motor is disengaged through .the clutch by the contact of pin |62 with the arm 61 of the clutch lever, turning said clutch lever, and the engagement of the arm 66 of the clutch lever with the collar 65 on shaft 5| slides the shaft 5| to the right, thereby separating the clutch parts 6|, 62.

The momentum of the carriage C after the cam 23 comes into contact with the marginal stop 26 to initiate the de-energization of the motor, and after the de-energization of the motor,

will carry the carriage to the limit of its return movement permitted by the marginal stop 26. The mechanism will however act to return the carriage to its marginal position from any position short of its fully returned position.

The character of the gears 53, 54 (described as helical gears) is of importance to the operation of quickly disengaging the clutch parts 6| and 62. As the abutment 24 on the carriage moves against 'the marginal stop 26 there is a recoil or force produced which is oppositeI to the driving This recoil is transmitted through the drumand shafts 36 and 5|, to the clutch parts. The helical gears 53, 54 permit of easy movement in either direction of rotation. The recoil acting on gear 54- tends to produce movement of the gears 53, 54 in an opposite direction to the direction in which they are driven by the motor and this is transmitted to the armature causing it to move in the opposite direction, and therefore instead of the clutch and gear parts being jammed together by the force of reof a typewriter, whereby when said carriage-stop' coil, the clutch-parts are free to move away from one another, because the force of recoil can act on the armature of the motor through the helical gears 53, 54, and relieve the pressure on the clutch teeth, and when the pressure of the clutch teeth is so relieved the clutch parts move apart easily and instantly under the action of the spring |80.

In the position of the carriage with the abutment 24 in contact with the marginal stop 26 the carriage-return key |15 may be struck as many times as desired to effect as many increments of the line-spacing as desired, the 'bar |50 beingadvanced to effect the energization of the motor 30 and the turning of the drum 34 each time that the key |15 is depressed, and the'bar |50 breaking the circuit to the motor`30 almost instantly and in the same movement of the key-lever |15, as the pawl |12 thereon slips olf of the pin |10 andreleases the bar to be shot back by its spring |80, the detent |66 in the position of the carriage C referred to being held depressed and out of position to engage the pin |64 on the bar by the pressure of the lower end of lever 205 against the pin 2|| on the said detent |66. V

AS the carriage C moves to the left in Fig. 1 in the operation of typing, or as the carriage is shifted back and forth manually, tension is maintained on the tapev 38, so as 'to .avoid slack occurring therein, bythe spring |30 attached to the drum 34, as heretofore described. The tension of the spring- |30, however, is not sufficiently great to actuate the handle L of the line-spacing mechanism. The drum 34 and shaft 36 being disconnected from the motor through the clutch,

of typewriter to which the carriage-return.

mechanismis applied.

The invention may receive other embodiments than that herein specifically 1illustrated and described.

What is claimedis:

1. Carriage return mechanism for typewriters, comprising an electric motor, means for connecting lthe motor to the carriage of a typewriter, andy means for starting and stopping the-motor cornprising a switch, a reciprocatory bar through which said switch is opened and closed, a spring Vacting on said bar in a direction to move the bar to switch-opening position, a manual key-lever having a pawl thereon for directlyvengaging said bar to move it against the tension of said spring to switch-closing position so that said bar may be moved to switch closing position irrespective of 'the position of the carriage, a. detent for retaining said bar, against the tension of said spring, in switch closing position, and carriage,

actuated means for automatically tripping said detent to release said bar.

2 A combination according to claim 1, wherein saidtripping means comprises a vertical lever strikes said horizontal movable element the detent is'operated to release said bar with a minimum of resistance and the switch is opened by the movement of said bar under the action of the spring acting thereon. l

3. Carriage return mechanism for typewriters comprising an electric motor, means including a clutch for connecting the motor to the carriage of a typewriter, and means for Ystarting and stopping the motor comprising a switch, a reciprocatory bar through which said switch and clutch are opened and closed, a spring acting on said bar in a direction to move the bar to switch and clutch opening position,'a manual key lever having a pawl thereonfor engaging said bar to move it against the tension of said spring, to switch and clutch closing position, so that said bar may be moved to switch and clutch closing position irrespective of the vposition of said carriage, a detent for retainingsaid bar, against the tension of said spring in `switch and clutch closing position, lc arriage actuated means for automatically tripping said detent to release said bar, and means for mounting said return mechanism on a typewriter.

4. A combination according to claim 3, wherein said tripping means comprises a vertical lever arranged to contact with said detent, and a horizontal movable element arranged to contact with said vertical lever and witha stop on the carriage of a typewriter, whereby when .said carriage-stop strikes said horizontal movable element the detent is operated to release said bar with a minimum of resistance and the switch and clutch are opened by the movement of said bar under th action of the spring acting thereon.

5. A combination according to claim 3, in

which the means for operating said switch and clutch comprise arms on said switch and clutch extending into the path lof said bar.

6. A combination according to claim 3, in

which the means for operating said switchand clutch comprise arms on said switch and clutch extending into the path of said bar, means on said bar engaging said arms in a direction to move said arms to open the switch and clutch Iwhen the bar is released by said detent, and

springs for moving said arms to close said switch and`clutch when the baris moved, against the tension ofv the spring actingthereon, by the manual key-lever, said latter (bar-actuating) spring being of suiiicient strength to overcome both .of said arm-moving springs. '7. A combination-according to claimI 3, wherein said means for connecting the motor to the carldrurn and ladapted to be connected to the carriage, and a light winding-spring acting to turn said drum in the same direction as it is turned by the motor and to maintain a tension on said cord when said clutch is,y operi and the carriage is moved back and forth manually.

8. A combination according to claim 3. said mounting means including -a single fiat plate/- separate from a typewriter frame, and means thereon for supporting lsaid motor, clutch, bar, key-lever, and detent,

'9. A combination according to claim 3, said frame, and means'attached to the portionsof said plate in said outside area for supporting i said motor, clutch, bar, key-lever and detent.

10. A combination according to claim 3, in which said means for connecting the motorto the carriage comprises reduction gearing between said motor and clutch, said reduction gearing consisting of gears of a type which are capable of transmitting turning movement with equal facility in either direction, whereby the shock of impact of a carriage which is stopped while connected through said connections to the motor will ltransmit an impulse through said connections in an opposite direction to the direction of action of the motor, the impulse acting through said gears to reverse the direction of turning of the motor and thereby relieve the pressure between the engaged parts of the clutch and ease the opening of the clutch by the spring acting on said bar.

11. Carriage return mechanism for typewriterscomprising a single fiat plate, separate from a typewriter frame and having portions lying outside of an area corresponding to the area of the underside of a typewriter frame, a motor, and a drum for winding a cord adapted to be attached to the carriage of a typewriter, said motor and drum being attached opposite one another to the portions of said plate in said outside area at the same side running from front to rear, a shaftA running the length of said frame between said drum and motor, means including a clutch between said motor and shaft, and means for starting and stopping said motor comprising a switch on said plate, a bar on said plate running parallel to said shaft lengthwise of said plate from front to rear, arms on said clutch and switch extending into the path of movement of said bar, and a manual key-lever on the front portion of said plate adjacent the front end of said bar ior actuating said bar.

FREDERIC W. LE PORIN. 

